<!DOCTYPE html>
<html lang="cn">

<head>
    <meta charset=utf-8>
    <meta name=viewport content="width=device-width,initial-scale=1">
    <title>互金项目</title>
    <link rel=stylesheet href=http://at.alicdn.com/t/font_572980_zu4ylhb5khdunmi.css>
    <link href=https://cdn.jsdelivr.net/npm/animate.css@3.5.1 rel=stylesheet type=text/css>
    <script>
        (function () {
            //得到手机屏幕的宽度
            let htmlWidth = document.documentElement.clientWidth || document.body.clientWidth;
            //得到html的Dom元素
            let htmlDom = document.getElementsByTagName('html')[0];
            if (htmlWidth > 1200) {
                console.log(htmlWidth);
                htmlWidth = 556 + 'px';
            }
            //设置根元素字体大小
            htmlDom.style.fontSize = htmlWidth / 25 + 'px';

        })();
    </script>
</head>

<body>
    <div id=app></div>
</body>

</html>
<html>